刚开始使用github时，代码库地址是使用的https的方式，因为这样简单，避免了设置ssh-key的麻烦。 但在使用linux的git管理代码时，每次git push代码时，就需要输入用户名，和密码。
下面将版本库https方式修改为git
git remote rm origin
git remote add origin git@github.com:用户名/版本库名.git上面代码移除原来的https方式远程库，然后添加git方式远程库
然后在本地生成rsa的key
ssh-keygen -t rsa -C “用户名”
然后出现一串提示，一路回车
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:42Qmnz4G3ZYbTEmmYTxCNoMbYBb1UU3yfGmRSBNy6fc bianpeijiang
The key's randomart image is:
+---[RSA 2048]----+
| =+.o*o++*+.. |
| o oo.+=**..o |
| o.o Bo.+ |
| . . +o. |
| ..S+ o . |
| .B.o* E |
| .+. o |
| .o . |
| ... |
+----[SHA256]-----+根据上边提示， ssh-key放在 /root/.ssh/id_rsa.pub文件中
cat /root/.ssh/id_rsa.pub
即可看到内容，复制
打开github.com中添加ssh key的地方 设置中的SSH and GPG keys，添加进去。
git push尝试
fatal: The current branch master has no upstream branch.
To push the current branch and set the remote as upstream, use
git push --set-upstream origin master
根据提示执行
git push –set-upstream origin master
最后会出现Everything up-to-date 说明成功。